Rick Rubin has had quite an interesting career in music. After co-creating the legendary Def Jam label with Russell Simmons, he has been responsible, in some ways, for the great careers of The Beastie Boys, LL Cool J and Run DMC, among others. After establishing his own American Records, he worked with Rock groups, producing for Rage Against the Machine, The Red Hot Chilli Peppers, Linkin Park, Slipknot and many more. Still, he continued to work with Hip Hop artists, signing The Clipse to Columbia Records and reemerging as a hit making producer for Jay-Z's "99 Problems."

As the years went on, fans could see a transformation in Rubin. When he started, he was a fresh face, a thin young man working to make Rap a viable genre. Later, he gained weight, grew a very long beard and seemingly became more calm. Fans can expect another transformation of sorts now.

During a recent interview with GQ, Rubin admitted to dropping 130 pounds through strict workouts and dieting. For the interview, Rubin appears shirtless and is interviewed alongside Kid Rock, the latest musician to be working with the producer.

"That ****er lost 130 pounds," Rock noted. "He was in the studio cutting apples and drinking his shakes."